


M A G N E S I U M ! ! !

by MarowDtymallei



Category: Assassination Classroom
Genre: Chemistry, Chemistry Nerds, Crack, Crack?, Dancing, Dancing and Singing, Dorks, Dorks in Love, Elements of the Periodic Table, F/M, Fluff, Fluff and Crack, Holding Hands, Humor, Korosensei Ships It, OOC, Periodic Table Song, Singing, Songfic, Wholesome
Language: English
Status: Completed
Published: 2021-01-04
Updated: 2021-01-04
Packaged: 2021-03-14 08:14:37
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,665
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28542366
Author URL: https://archiveofourown.org/users/MarowDtymallei/pseuds/MarowDtymallei
Summary: Okuda's feeling pretty down after her latest poisoning attempt on Korosensei was another failure. So while cleaning up the chemistry lab, she tries to cheer herself up. She begins singing one of her favourite songs that her invulnerable teacher has taught her: The Periodic Table Song. Little did she know that a certain red-haired classmate of hers hadn’t left campus yet, and that the same classmate was ready to make an entire epic musical number alongside her.Basically, Karma and Okuda prance around an empty chemistry lab passionately singing the AsapSCIENCE Periodic Table Song.
Relationships: Akabane Karma/Okuda Manami
Comments: 20
Kudos: 54





	M A G N E S I U M ! ! !

**Author's Note:**

> I saw the AsapSCIENCE Periodic Table Song becoming popular with Kuroo, but then I remembered another chemistry-loving character who would definitely belt out this song with all her heart. And Karma would definitely join in. I do not own the song or AssClass! Enjoy this crack!

“Ethylene glycol! What was I thinking?” Okuda muttered to herself as she walked into the empty chemistry lab. After carefully constructing a unique concoction of poisons with enough potency to kill an elephant ten times over, she had given it to her teacher after class. It was this one, _this one_ , she felt so sure about. Even after all the botched brews resulting only in a pair of horns or wings for Korosensei, this one was going to finally do the octopus in. 

Except— it didn’t. 

He drank the poison eagerly, as you do, and the contorting tentacles and shaking seemed promising, but the assassination attempt was yet another bust. He turned powder blue and sprouted some spiky scale-looking things this time. And Korosensei had to just rub it in and go on and on about how it was ‘the most deliciously nectarous poison he ever had’. On the bright side, the octopus was distracted enough for Karma to almost get a jab in with his anti-sensei knife. He missed, but it was the bloodlust that counted.

“I should have just given him antifreeze and saved myself the effort,” Okuda sighed. Now she was one of the last ones at school because she had to clean up the supplies she used to make her failure of a poison. Korosensei probably would have helped her, maybe even made a new poison for him with her, but Maehara and Isogai invited him to test out a trap rigged with BBs.

She should’ve cleaned up before she left (having chemicals lying about is dangerous!) but she was just so excited to give her teacher the poison. Wait, not a poison: A pointless mix of chemicals. It wasn’t really a poison if it didn’t do its job. She sadly cleaned and put away the different bottles and beakers that covered her station. 

As she wiped the wooden table, Okuda tried to put her mind on something besides the flubbed experiment. Glancing around the lab, memories of previous chemistry classes drifted through her mind. One memory that always brought a smile to her face was the class when Kayano mixed up magnesium and manganese, prompting Korosensei to sing a song about all the elements in the periodic table. The Periodic Table Song, although her teacher’s tone-deafness made for a slightly painful performance, turned out to have a catchy tune that Okuda couldn’t help humming in the days that followed. And she of course knew all the lyrics, what kind of chemist would she be if she didn’t know all one hundred and eighteen elements?

Actually, what kind of chemist would she be if she couldn’t even make a functioning poison?

 _No, away dark thoughts, away dark thoughts_ , Okuda thought as she slapped the sides of her face. There was only one way to get her mind off her crushing failure as an assassin/chemist, and that was to sing her favourite song.

Glancing at the two open doors to the right of her, Okuda decided she should be safe from any accidental walk-ins since it was the end of the school day. She clutched her cleaning rag with determination. She was _not_ going home miserable! She was going to cheer herself up, dammit!

Taking a deep breath in, Okuda began to sing.

“ _The elements of_ …” she sang quietly and delicately, already feeling a grin slipping onto her face, “ _the periodic table!_ ”

With a rising giddiness, she wiped down the counter top in time with the song, singing the first few elements: “ _there’s hydrogen and helium, then lithium, beryllium._ ”

Why clean just her table? She should clean all the tables!

“ _Boron, carbon everywhere,_ ” her singing was growing more confident, and she bounced on her toes as she wiped the remaining tables, “ _nitrogen all through the air._ ”

No more tables? Time to flourish the cleaning rag like it’s a dancing scarf!

“ _With oxygen so you can breathe, and fluorine for your pretty teeth,_ ” Okuda was getting pretty into it. Even better, she could feel her gloominess evaporating with each element she sang.

She spun the rag around, doing a little dance back and forth. She laughed a little at the thought of anyone walking in on her, jamming out to a nerdy song all alone in the chemistry lab. She laughed, because it was such an improbable idea.

She continued to happily sing out, “ _neon to light up the signs, sodium for salty times—_ ”

“ _MAGNESIUM!_ ”

Okuda squeaked and jumped nearly a foot in the air. Swiveling around, she looked up and locked eyes with a grinning Karma Akabane. Okuda dropped her rag/dancing scarf. Her face paled. Her face then quickly reddened like a tomato.

Even with all her assassination training, if Karma really wanted to be stealthy there was no hope of her detecting him even in a million years. Shouldn’t he have gone home already? Why did it have to be _Karma_ of all people to walk in?

And that big, goofy grin was concerning. Not one of his sly, evil grins, not a condescending smirk; just a huge, bright grin one could almost call a smile. He didn’t have his chin tilted up in his usually cocky stare. Instead, he faced her head on. The beat of silence between them only made Okuda’s face burn even hotter.

She meant to ask him what he was still doing here, but with half her mind still on the song instead she asked—

“ _A-aluminum, silicon?_ ”

No, that was even more embarrassing—! 

“ _PHOSPHORUS!_ ” He shouted back at her, no, _sang_ back at her. The smile on his face turned brighter. It took Okuda a split second to realize.

_Oh. Oh!_

She beamed at him, still scrunching up her fists a bit nervously. If anything would make her forget about her assassination attempt, it would be this.

“ _Then sulfur, chlorine, and argon!_ ” She chirped back happily.

“ _POTASSIUM!_ ” Karma seemed just as giddy as she was. Okuda thought math was more his forte, but then again, Korosensei’s math songs weren’t really something to get hyped about.

“ _And calcium so you’ll grow strong._ ” Okuda flexed her biceps in a strongman pose, laughing.

“ _SCANDIUM!_ ”

Then, together, they sang “ _titanium, vanadium and chromium and manganese~_ ” holding out the final note. 

She didn’t know what possessed her to do this, but in that pure moment of jubilation, Okuda took his hands and hers and started spinning. Karma didn’t pull away; instead, he held on tighter as he sung the start of the chorus.

“ _This is the periodic table—_ ” 

“ _—noble gas is stable!_ ” Okuda chimed in.

They spun around the classroom, dodging counters and stools. _How can Karma’s smile be so pure?!_

“ _Halogens and alkali react aggressively,_ ” they sang in unison, now practically skipped in a circle, “ _each period will see new outer shells, while electrons are added moving to the right!_ ”

They released each other with a flourish. Twirling, Okuda pointed both fingers at Karma, singing “ _iron is the twenty-sixth!_ ”

“ _Then cobalt, nickel coins you get._ ” Karma pointed back at her, grinning.

“ _Copper, zinc, and gallium. Germanium and—_ ”

“ _ARSENIC._ ” Karma cackled. 

“ _Selenium and bromine film,_ ” Okuda snorted, trying to keep in tune.

“ _While krypton helps light up your room._ ”

“ _Rubidium—_ ”

“ _And strontium—_ ”

“ _Then yttrium—_ ”

“ _Zirconium—_ ”

Both of them threw their hands up in the air, singing “ _NIOBIUM!_ ”

“ _Molybdenum, technetium,_ ” Karma sang. The two held hands again, picking up the reeling pace again.

“ _RUTHENIUM!_ ” 

Okuda sang the next elements, her pigtails almost slapping her in the face as they spun, “ _Rhodium, palladium,_ ” 

“ _SILVER-WARE,_ ” Karma and Okuda practically screamed, “ _then cadmium and indium._ ”

“ _TIN CANS!_ ” He sang, throwing his head back as the pair spun faster and faster.

The classroom was swirling in Okuda’s dizzied eyes, but she took in a deep breath before she sang the elements in rapid succession, spinning faster and faster, “ _antimony, then tellurium, and iodine, and xenon, and then caesium, and—_ ” 

A hand slipped around Okuda’s waist and quickly pulled her away from the counter corner she was about to hit. This would have been all fine and dandy, except the proximity between the two classmates was now closer than either of them had ever been. A beat of silence passed, during which Okuda’s face took on several new shades of red as she and Karma just stared into each other’s eyes. Karma looked almost puzzled, probably wondering why he was still holding her tightly to him. _Great, now I’m going to go home miserable_ and _embarrassed._

But Karma’s confusion melted from his face, replaced with a grin. 

“ _Barium is fifty six, and this is where the table splits,_ ” his voice was now coming out gentle and beautiful, like velvet against her ears. Okuda froze, transfixed by her classmate's voice. This was the first time she’s heard the song sung with such elegance. Korosensei had only ever squawked/screeched it at them. 

As for Karma’s borderline hypnotic voice, it did make sense: With how smooth his everyday voice was, of course he’s going to be able to sing like a siren.

“ _Where lanthanides have just begun,_ ” Karma continued, slowly intertwining his hand with hers. “ _Lanthanum, cerium, and praseodymium~_ ”

The moment didn’t have the same embarrassment as it did before, although Okuda still felt the same butterflies in her tummy. She squeezed his hand, staring up at him, a small smile on her lips. The song would still go on.

“ _Neodymium’s next to promethium then sixty-two._ ” 

Okuda wasn’t going to let him hog all the lyrics. “ _Samarium, europium, gadolinium and terbium,_ ” she inhaled deeply for the fast part, “ _dysprosium, holmium, erbium, thulium—_ ” 

“ _Ytterbium, lutetium~_ ” Karma held the high note. The easy way he held her was almost comforting. Another moment of silence followed, before the redhead stepped back.

Before Okuda could feel disappointed, he swiftly pulled her up onto the counter top with ease. There the two were, alone in the chemistry lab, standing on a counter, hands together, giddy like grade schoolers.

They both took a deep breath.

“ _Hafnium, tantalum, tungsten then we’re on to,_ ” Karma and Okuda sang in excitedly, “ _rhenium, osmium and iridium._ ”

Okuda started a pushing a pulling rhythm of their hands, singing “ _platinum—_ ”

“ _Gold to make you rich ‘till you grow old,_ ” Karma followed her motions, pulling a laughing Okuda onto one of the adjacent counters with him, “ _mercury—_ ”

“ _To tell you when it’s really cold,_ ” she sang. With a rising confidence, Okuda pulled Karma onto another counter as the song picked up.

“ _THALLIUM!_ ” The pair screamed as they leapt across the counters. “And lead and bismuth for your tummy!”

“ _POLONIUM! Astatine would not be yummy!_ ” They danced and bounced around each other, laughing as they sang. “ _RADON! Francium will last a little time!_ ” Hopefully they wouldn’t leave any footprints.

“ _RADIUM! And actinides at eighty~ nine~_ ” Okuda tried to hold the note with Karma, and this time he wasn’t doing his serious siren singing voice, which she was grateful for. For the final chorus they jumped back to the floor where they could have more dancing space.

“ _This is the periodic table, noble gas is stable, halogens and alkali react aggressively!!_ ” Alkali wasn’t the only thing that was aggressive. If Okuda ever felt this brave again, she and Karma should enter a dance competition because their moves were fire. 

“ _Each period will see new outer shells while electrons are moving to the right!!_ ” Karma pointed at her, signaling for her to carry on the song.

“ _Actinium, thorium, protactinium,_ ” Okuda sang in tune, but almost faltered because Karma Akabane was vocalizing while she was singing. And he was good at it, too. Okuda wanted to know more of Karma’s hidden talents, but they had to finish this fantastic musical number first.

“ _Uranium, neptunium, plutonium,_ ” they had moved so close together, their voices molded into one. Okuda took a deep breath for the next slew of rapid lyrics. Karma sped up his vocalizing (psychotic delinquent Karma Akabane can not only hold a high but also _vocalize_ ).

“ _Americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium, lawrencium, rutherfordium, dubium, seaborgium, bohrium, hassium, meitnerium, darmstadtium, roentgenium, copernicium,_ ” Okuda breath ran out just in time. Karma held both her hands again as they finished the falling verses.

“ _Nihonium, flerovium,_ ” Karma smiled down at her.

“ _Moscovium, livermorium,_ ” Okuda blushed slightly but beamed up at her classmate, her wonderful friend who had turned her mood around.

“ _Tennessine and oganesson,_ ” Karma sang the final elements, and the two finished with a satisfying “ _and then we’re done~_ ”

They dragged out the note a little longer than they should’ve, but Okuda didn’t want it to end. She didn’t think Karma did, either.

“That was fun, Okuda. I’ve never heard you sing like that before, or at all, for that matter,” Karma said pleasantly. 

He was back to his normal conversation voice. But now that the gusto of the song was fading, the nearness of her and him made goosebumps run across her skin and her face flush. Though, surprisingly, Okuda didn’t want to be the first to break away from his warm hands.

“Your voice is magical, especially compared to mine.” She looked away, holding on a bit tighter. If he noticed (which he obviously did), he didn’t tease her.

He squeezed back.

“Karma—” Okuda breathed. She looked up at her classmate. Her heart felt like a sparrow trapped in a cage; beating fiercely as if fighting to break free. Karma’s eyes never once left hers. “Karma… Can you… Come closer?”

“Always.” He untangled his hands from hers, inside wrapping his arms around her small frame. Okuda hugged back, nuzzling into his shoulder. _So warm_ , she thought. Lips by his ear, she whispered quietly:

“You’ve noticed Korosensei watching us from the window, right?”

“Yeah, he’s been there since barium. You know the octopus would never miss his OTP singing and dancing together,” Karma murmured, an amused lilt in his voice.

“We’re his OTP?” Okuda giggled into him.

“Well, we outrank Nagisa and Kayano, that’s for sure.”

“We should probably clean up the counters since he’s watching.”

“I love how you’re such a goody two shoes,” Karma smiled. Okuda jokingly huffed. “Let’s leave the work for the peeping tom. He wouldn’t want to disturb our precious moment with cleaning if we leave campus holding hands.”

“I like the sound of that, Karma,” she whispered. Even if Karma couldn’t see her blush, Okuda knew he could definitely feel it. 

The two broke away, intertwining fingers again quickly. In the corner of her eye, Okuda could see her bubblegum-faced teacher and an obnoxious flash of a camera. This must be how celebrities felt. But even if she and Karma ended up in the yearbook later, having this beautiful time with him now was worth any amount of embarrassment. 

“I really loved seeing that side of you, Okuda,” Karma said honestly, looking forward as they left the classroom. “I hope I can see more of it.”

Her voice caught in her throat. She could only nod, trying to suppress her blush and growing smile. 

The sunlight streamed through the windows as they walked through the hallway, hand in hand. She felt warm. Okuda definitely wasn’t going home miserable.

“Now, to get revenge on the creepy octopus,” a glint of mischief sparkled in Karma’s eyes, “I’m thinking something messy and involving acid. Something to disorient him and leave him vulnerable to my knife.” His smile was maniacal, as per usual with Karma Akabane. It was familiar to Okuda, and after the musical they performed, Okuda plucked up the courage to ask something she’d been wanting to for a long time.

“I’ve been meaning to test some acids on him, so I can help you there. Do you, uh, want to plan the assassination over some coffee or something?” Okuda asked, prepared to get brushed off.

“Ooh, yeah I know the perfect café! You have to try the crêpes, it’s like heaven covered in whipped cream.” Karma said excitedly, quickening his pace and tugging Okuda along with him. Her heart soared. 

Yes, Okuda was definitely _not_ going home miserable.


End file.
